Thomas j



i T. J. FAY.

PROCESS OF TEMPERING METAL.

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1,1 94,829, Paten ed Aug. 15, 1916 WM%@M- THOMAS J. FAY, OF BROOKLYN, NEW YORK, ASSIGNOR TO PERFECTION SPRING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

PROCESS OF TEMPERING METAL.

Specification of Letters Patent.

Patented Aug. as, rare.

Application filed November 6, 1913. Serial No. 799,480.

To all whom it may concern:

Be it known that I, THOMAS J. FAY, a citizen of theUnited-States, residing at Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Improvement in Processes of Tempering Metal, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to a process of tempering steel. While the process and apparatus whereby the process is realized are adapted for tempering other articles, it is contemplated that one of the principal fields of usefulness of the invention will be the tempering of steel plates, such as are used in the manufacture of flat-leaf springs. One of the objects of this invention is to provide a process of quenching heated steel articles by the use of a series-of quenching tanks any oneof which may be used, the temperature of the liquid in the several tanks being maintained practically'uniform by a circulation which at least'in partdepends on the rise in temperature produced in any tank by the article immersed therein.

Further objects of the invention will appear hereinafter in connection with the .description.

In the drawings forming part hereof Figures 1 and 2 represent each a diagrammatic sectional view of a series of liquid-containing tanks, with means for circulating llquid through said tanks and means for cooling such liquid outside of said tanks.

In the said drawing (referring particularly to Fig. 1), A represents a tank for thequenching liquid, which preferably will be oil. This tank is provided with an inlet connection for a conduit B, the inlet connection being located near the bottom and at one end of the tank. C denotes a stand pipe, which extends through the wall of the tank opposite the inlet connection and-which is shown as connected with the adjacent wall of a second tank A, above the bottom thereof,in substantially the same position as the point of connection between the conduit B and the first mentioned tank. A number of tanks, A, A, A and A are shown, all of the said tanks being connected in series, with the stand pipe' of one tank discharging through the adjacent wall of the next adja* cent tank. The outlet from the last tank in the series communicates with a pump E, the

, any other well known manner.

delivery end of said pump discharging the 011 received from said tank into a cooling device F, which is preferably a pressed-steel radiator wherein the heated liquid is spread out into a series of thin disks, the radiator sections being exposed to a cooling liquid in the tank G, which liquid may be circulated through the tank by means of a pump, or in From the cooler F the oil is delivered through the conduit B to the tank A, in the manner herein- -before described. When the heated plate is introduced into the tank A, the oil at and near the surface first boils up as the hea ed metal strikes the same. A high level of the oil is produced, not only by the displacement of the oil by. the immersion of the metal thereinto but by the boiling and-swelling of the oil under the heat imparted by the plate. This heated oil, at the top of the tank, is removed at once by the skimmer, the plate meanwhile being lowered into the cool current of oil entering through the inlet pipe at the bottom of the tank, which oil flows in a stream along the plate when the latter is at or near the bottom of the tank, thus not only quickly quenching the plate but wiping off any heated oil that might otherwise adhere thereto and preventing any spheroidal action is prevented, and the, steel is quickly and uniformly quenched, whereby it is tempered in the most'eificient manner. While heated oil is shown as being discharged from the tank A into the tank A and thence through each succeeding tank in the series, it has been found in'practice that economical and efficient results are realized by placing a plurality of tanks inseries (say five) and, by circulating a large body of the cooling liquid, realize a very considerableheat interchange,

with a low difference in sensible temperature,

so that the presence of several tanks in series does not prevent or impede the realization of a practical result. For instance, if the total difference in sensible temperature is five degrees for five tanks, and five hundred pounds 'of the quenching liquidis handled and cooled per minute, allowing 0.5 B. T. U. per pound, then fifty B. T. U. of heat will be absorbed er tank, taking the average of the tanks. owever, if one tank of the series is taking more steel than another, then, by having, say, five tanks in series, thetank that maximum work.

tion shown in Fig. 1.

is being overworked, as it were, is being helped out by the tanks that are not up to It will be understood that the several heated articles are immersed in the different tanks respectively, at the same or difi'erent times.

In Fig. 2 of the drawing there is shown an arrangement which difiers from that shown in Fig. 1 in that the tanks are connected in parallel instead of in series. In Fig. 2, B denotes a supplyconduit having branches B each of which is connected to the bottom of one side or end of one-of the aforesaid tanks. Each branch B may be provided with a valve B whereby any tank in the set may be put into and out of operation, irrespective of any other tank. Each 'tank is. provided with a stand pipe C, similar to the stand pipe C and similarly located, each stand pipe communicating with a common outlet manifold H, said manifold com municating with the inlet side of the pump E. This pump is shown as having its discharge side connected with a radiator F, similar to the radiator F, saidradiator being located in the tank Gr through which the cooling liquid is circulated in the same manner as in the embodiment of the inven- It will be evident that the tank A, shown in Fig. 2, is substantially identical in operation with the tank A of Fig. 1. It will also be evident that each tank in Fig. 2 is more independent of each other tank than is the case with the earlier-described embodiment of the invention; also that the tanks do not so completely aid each other as they do when connected in series.

In both systems, however, means are provided whereby the article to be tempered is effectively cooled and whereby the tempera- ,ture of the quenchingliquid is maintained 1. The process of tempering which consists in circulating a quenching, liquid through, a cooler and a connected series of tanks and immersing heated articles in said tanks respectively.

2. The process of tempering which consists in circulating a quenching liquid through a series of tanks each of which has a hot liquid overflow outlet at the top and a cool liquid inlet at the bottom, whereby the temperature of the liquid in the tanks is equalized, and immersing heated articles in said tanks.

3. The process of tempering which consists in circulating a quenching liquid through a cooler and through a succession of tanks arranged in series with an overflow connection from one tank to the lower through said baths, the circulation in each bath being proportioned to the rise of temperature therein produced by the article being tempered.

In testimony whereof, I hereunto aifix my signature in the presence of two wit-.

nesses.

- THOMAS J. FAY. Witnesses:

BRENNAN B. WEsT, JOHN G. U'rz. 

